[Discuss-gnuradio] FFT filters--still a problem with filter growth

[Marcus D. Leech]

I thought the problem with FFT filters growing after initial 
construction was gone in recent Gnu Radio,
  but it's back.

I'm running the latest "next" branch, along with UHD.

Create an FFT filter of length X.  If the filter coefficients change at 
run time and the resulting
  length is longer than the initial X, the flow-graph seems to wedge 
(the previous failure mode for this
  caused it to dump core).

If I change my code so that the initial filter size is as big as it will 
ever need to be, I don't get any
  problems.

I have a tap generator for the FFT filter that produces filters whose 
lengths are powers of 2,
  to hopefully improve performance.  But if the initial filter is 
(let's say) length 4096, and then
  dynamically changed to 8192 or 16384, etc, then the flow-graph seems 
to wedge.